1. Field of the Invention
The present invention is related to vehicle air intake components and, more particularly, to air intake components that remove hydrocarbons from an air intake system when the vehicle engine is not in operation.
2. Background Art
Evaporative emission regulations that vehicles require the control of polluting substances (primarily hydrocarbons) from the vehicle as it sits unused. These emissions are leaked out of the vehicle from many sources including the air intake system. In the past, only those from the fuel tank were captured, with carbon-filled canisters, but this has now been expanded to the entire vehicle. Newer regulations require control of emission of harmful substances from the air inlet system of the powertrain when the vehicle is at rest (not in use). These substances need to be retained within the air inlet system until the powertrain is again used when the retention system will give up the harmful substances to be consumed and controlled through the normal exhaust emission control systems.
There are several ways to control the outward flow of pollutants from the air intake system of an automobile. One such technique is the careful shaping of the ducting and filter box. However, this method is often not sufficient to meet the regulatory requirements. Accordingly, other methods must be used such as the incorporation of systems in the air intake system that use some form of carbon or other material to absorb the pollutants during the rest cycle. When the vehicle is next started, the in-rushing air will draw the pollutants from the absorbent and deal with them through the normal exhaust system pollution controls. This inward air rush also regenerates the absorption systems so that they may be reused. Unfortunately, these extra absorption systems add cost, weight and complexity to a vehicle and often restrict the air flow.
Many vehicles, especially with smaller engines, use an air intake system for the powertrain which uses in part a porous material for noise attenuation. Most often, this is on the xe2x80x9cdirtyxe2x80x9d side before the air reaches the air intake filter. Sometimes the porous material is used after the filter with a wrapping to keep dirty air from being drawn in through the pours from outside. However, such noise attenuation does not remove pollutants from a vehicle air intake system to any significant degree.
For the reasons set forth above, there is a need for an improved air intake system that removes pollutants when a vehicle is not in use that does not significantly add cost, weight or complexity to the vehicle design.
The present invention overcomes the problems encountered in the prior art by providing a hydrocarbon-removing component for a vehicle air intake system of an internal combustion engine that comprises a duct having an inner surface and a cross-section and a hydrocarbon-removing material incorporated into the inner surface of the duct. The cross-section is of sufficient size to allow air to flow into the internal combustion engine during operation. Accordingly, the component of the present invention removes hydrocarbons when exposed to the air in the vehicle air intake system when the internal combustion engine is not in use.
The hydrocarbon-removing component of the present invention is advantageously integrating the hydrocarbon-removing material into an existing air intake component. Such components include the air inlet, the air filter, the resonator, and the clean air tube. For example, if a vehicle uses a porous duct for the control of noise, whether before or after the air filter, the porous duct can be coated or impregnated with carbon or similar material to absorb pollutants. This takes advantage of the great surface area of the porous ducting to increase the absorption capabilities of the duct. Thus a preexisting part with slight and inexpensive modifications can be made to serve two functions and eliminate the need for the addition of a separate absorption device. Alternatively, if the vehicle still requires an absorption device to meet emission regulations, by coating or impregnating the porous duct with carbon or other absorption materials, the absorption device can be made smaller, less expensive and less restrictive by the inexpensive addition of an absorbing material to a device which is already in place for noise attenuation. If the porous duct is on the xe2x80x9cdirtyxe2x80x9d inlet side, it can be encased in a solid wall duct or sleeve to keep the pollutants from escaping through the duct walls into the environment. The porous material is typically made from a natural or synthetic fiber which is woven, spun or otherwise formed into the duct.
In another embodiment of the present invention, a method of forming the hydrocarbon-removing component of the present invention is provided. This method comprises adhering a hydrocarbon-removing material to the inner surface of a section of an air intake component with an adhesive capable of withstanding temperatures from xe2x88x9240 to 300 degrees F.
In yet another embodiment of the present invention, a second method of forming the hydrocarbon-removing component of the present invention is provided. This second method comprises combining fibers, a hydrocarbon-removing material, and a binder together to form a premix. The premix is then pressed together to form a sheet which is cut into a pattern that can be formed into a duct.